“If the police do decide to investigate I will fully cooperate with their inquiries, including giving them full access to all my financial records from the General Election campaign. I am confident that no case will be found and I will be fully exonerated.”

Ms Smith’s team said her 2015 campaign expenditure was £2,000 below the maximum allowed. The Guido Fawkes article suggested her claims were low – insinuating she actually spent more. The blog said of her election office premises, on Lord Street, Fleetwood: “The office is listed online with an annual rent price of £8,950. Yet throughout the campaign, more than four months, Smith declared just £1,544.60 in office rent.”

And on staff, it was claimed: “In the long campaign Smith declared £692.25 in staffing costs, in the short campaign she declared another £576.88. Yet the job advert for the Fleetwood organiser stated that the salary was £22,547 per annum.

“Remarkably, Smith claims her organiser Ben Singleton spent just 12.5 per cent of his time on her general election campaign, and spent the vast majority helping the national campaign and council candidates. But during the election Singleton tweeted exclusively about Smith.”

In response, her campaign agent James Groves said: “The property was rented by the party and supplied to Cat Smith’s campaign and the Wyre Borough Council candidates’ campaigns. The rent was £2,013.50 per quarter, equating to £2,228.64 over 101 days, and 50 per cent of this total was charged to Cat Smith’s campaign (the rest was charged to local candidates in Wyre).”

He said the actual amount was £1,114.32.

He also said: “Ben Singleton was employed as an organiser by Labour North West during the long campaign with 75 per cent of his time allocated to the Labour Party’s national campaign and 25 per cent to local campaigns. “This was split between Cat Smith’s campaign (12.5 per cent) and local council candidates in the constituency (12.5 per cent). The amount was £692.25.

“The practice of dividing an organiser’s time was, and is, standard procedure.”

A spokesman for Lancashire Police said: “We have received a complaint and we are in the early stages of looking into the matter to establish whether there is anything to substantiate the allegations being made.”